Japanese Patent Application Publication No. 2015-002277 describes a switching element provided with a SiC substrate. The SiC substrate includes an off-angle. Basal plane dislocation (BPD) exists within the SiC substrate. When current flows in the SiC substrate, carriers recombine within the SiC substrate. Plane defects grow with the basal plane dislocation as their starting points by recombination energy generated upon the recombination. The plane defects grow along a {0001} plane. When the plane defects grow, a resistance of the SiC substrate increases, and a loss generated in the switching element increases.
The switching element of Japanese Patent Application Publication No. 2015-002277 is provided with a plurality of current restricting regions located inside a drift layer. The current restricting regions are constituted of p-type layers. The plurality of current restricting regions is arranged dispersedly within the drift layer. When the plane defects grow in the drift layer, the plane defects reach the current restricting regions. Recombination energy supply to the plane defects is suppressed in the current restricting regions. Due to this, growth of the plane defects stops. Accordingly, the plane defects are suppressed from excessively growing.